I just got one.

Anyone have any tips for mod's that would improve it?

webarmory.ixworld.com/faqs/faqs.html

Haven't made it that far yet myself, also check Kurts Kustom Firearms on the industry doard. He does some cool stuff.

Quoted: I just got one. Anyone have any tips for mod's that would improve it?

The best mod I've seen out there is to sell it and buy a AR-15.  

Quoted: The best mod I've seen out there is to sell it and buy a AR-15.

Already got 3

Quoted: Sure.  The M17S' two weakest spots are the trigger and the original iron sights.  There are easy fixes for both.  First, do a little research, if you haven't done so already. Search using M17S keyword in both GD, and the Industry Forums. After that, I'll be glad to answer any questions that you might have, If I can. I think that I've solved most, if not all, of the worst problems of the M17S, and I don't mind sharing.

WELL GOOD GOD MAN! LET'S HEAR IT! GIVE IT UP!

I don't have the specifics, but I think RAF's were the posts that I printed off as future fixes for mine.

Definitely can use additional cooling slots, a lower scope mount and improved charging handle.  I thought at one point about having my wife sew up a Nomex foregrip cover.  When I shoot mine in the winter, it doesn't bother me, but in the summer it gets hot damn fast.  

I tried a couple of sights on it (casual plinking)--a 6x Redfield (too big/ungainly), a BSA red dot (not bad) and a Reflex 2--the best of the batch.  My only dislike is that it sits too high on the factory scope rail and it's base.

Nice guns--fun to shoot.

AFARR